Updates section header magnitude in Hardware docs
Updates section header magnitude in Hardware docs

Trying to get a more consistent folding in the navbar, by grouping the
various subsections into logical categories. Previously, "Optional
Hardware" was a subsection of "Required Hardware", which didn't make
sense.

ageis/securedrop,garrettr/securedrop,ageis/securedrop,heartsucker/securedrop,micahflee/securedrop,conorsch/securedrop,micahflee/securedrop,heartsucker/securedrop,conorsch/securedrop,ageis/securedrop,heartsucker/securedrop,ageis/securedrop,conorsch/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,micahflee/securedrop,conorsch/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,garrettr/securedrop,garrettr/securedrop,conorsch/securedrop